1. Field of the Invention
The invention relates to a rolling bearing device including a first bearing ring, a second bearing ring, rolling elements, and a pump that supplies lubricant.
A conventional rolling bearing device of this type is described in Japanese Patent Application Publication No. 2012-102803 (JP 2012-102803 A). The rolling bearing device includes a ball bearing, a tank, a pump, and a battery. The tank stores grease. The tank has a discharge port. The pump sucks in the grease from the tank and discharges the grease from the discharge port.
The pump is operated by electric power from the battery. In the rolling bearing device, the grease stored in the tank is moved to the discharge port and the grease is discharged to a raceway surface of an outer ring. In this way, sliding portions are lubricated.
In the rolling bearing device, the pump is operated by the electric power from the battery. Therefore, if the battery capacity is increased, the size of the rolling bearing device is inevitably increased. If the electric power for the pump is generated by a generator to avoid the increase in the size of the rolling bearing device, the reliability of electric power supply is not high in the present circumstances. Therefore, an improvement in the reliability of the electric power supply is absolutely necessary.
On the other hand, if the electric power for the pump is supplied from an external power source, a wire extending over the rolling bearing device and a housing, to which the rolling bearing device is fixed, is required. However, when a work for fixing the rolling bearing device to the housing is performed, the wire obstructs smooth fixation of the rolling bearing device to the housing.